Pork tenderloins are a great weeknight dinner option because they adapt well to many different flavors, and they cook relatively fast. To make this dinner even easier, we came up with a version that could be prepped ahead of time and cooked a day later. We started by rubbing the tenderloins with herbes de Provence, which was a simple way to provide a nice blend of flavors. Crumbling the herbs helped them to coat the pork more evenly. A hearty combination of apples and shallots nicely complemented the rich pork. With the flavors established, we turned to the cooking method. We seared the pork in a skillet to brown it, then transferred it to a plate while we browned the apples and shallots in the same pan, flavoring them with the fond from the pork. Then we nestled the browned pork into the apples and shallots to finish cooking gently in the oven. While the pork rested, we added butter to the apples and shallots for some extra richness.
Swap option: You can find herbes de Provence in most large grocery stores; however, 1 teaspoon each of dried thyme, dried rosemary, and dried marjoram can be substituted.
Season pork with herbes de Provence, salt and pepper, wrap with plastic wrap, and refrigerate for at least 1 hour. Meanwhile, toss shallots, apples, 2 tablespoons oil, and sugar together in bowl.2.
Adjust oven rack to lowest position and heat oven to 350 F. Pat pork dry with paper towels. Heat remaining 2 tablespoons oil in 12-inch oven safe skillet over medium-high heat until just smoking. Place both pork tenderloins in skillet, spaced 1 inch apart, and brown well on all sides, 8-10 minutes; transfer to plate.3.
Add apple mixture to now-empty skillet, discarding any excess liquid. Cook until shallots and apples begin to soften and brown lightly, 10-12 minutes. Off heat, nestle tenderloins and any accumulated juices into apple mixture, alternating thicker end to thinner end. Transfer skillet to oven and roast pork until it registers 145 F, 15-20 minutes.4.
Carefully remove skillet from oven (skillet handle will be hot). Transfer pork to carving board, tent with aluminum foil and let rest for 5-10 minutes. Stir butter into apple mixture, season with salt and pepper to taste, and cover to keep warm. Slice pork into ½-inch-thick slices and serve with apple mixture.